Expand volume to a different array

I have a DL385G1 with a 6i Smart Controller. There are 4 disks, 2 disks in a RAID1 array and 2 disks in a second RAID 1 array. The two logical disks are presented to Windows Server 2003 as C:\ and D:\ and are basic disks.

I want to extend the D:\ partition by adding a third RAID1 array/logical disk.

1. Can I convert the D:\ disk to dynamic disk to create a simple volume and expand the volume onto the unused space on the new array?